v4sta012.ansp.bluewin.org has no MX records.
Question and response
Question
dig v4sta012.ansp.bluewin.org. MX
Answer
The response has no answer records.
Authority
bluewin.org. 600 SOA dns3.swisscom.com. admin\.dns.swisscom.com. 7422 21600 3600 604800 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0